Flight Control Design for Alleviation of Pilot Workload during Helicopter Shipboard Operations

A flight control design methodology for alleviating pilot workload during helicopter shipboard operations was developed and tested in simulation. The methodology uses modern MIMO control theory to improve gust rejection properties when operating in a turbulent ship airwake. The spectral properties of the airwake are identified using simulations and incorporated into the control synthesis process. The controller design is constrained to represent a limited authority SAS. Model order reduction methods are used to simply the control laws for practical implementation. The methodology was applied to design a modified SAS for the UH-60A operating over an LHA ship. The system was implemented in a high-fidelity simulation model and its performance was compared to that of the baseline SAS. Simulations were performed of the helicopter hovering in the turbulent airwake using a pilot model for two different wind-over-deck conditions. Results indicate that the modified SAS resulted in significantly lower control activity and angular motion of the aircraft.